Magneto-electric transformer



P. RABBIDGE.

MAGNETO ELECTRIC TRANSFORMER. APPLICATION FILED 020.24.1919.

1,341 34QD Patented May 25,1920.

ATTY.

PARNELL RABBIDGE, OF NEUTRAL BAY, NEW SOUTH WALES, AUSTRALIA.

MAG-NETO-ELECTRIC TRANSFORMER.

Specification of Letters Patent.

Patented May 25, 1920.

Application filed December 24, 1919. Serial No. 347,176.

To all whom it may concern Be it known that I, PARNELL RABBIDGE, subject of the King of Great Britain and Ireland, residing at Hillmont, Reynold street, Neutral Bay, in the State of New South Wales, Commonwealth of Australia, have invented certain new and useful Improvements in Magneto -Electric Transformers, of which the following is a specification.

This invention relates to electrical machinery and has special reference to rotary transformers.

One important object of the invention is to provide an improved rotary transformer designed particularly to convert unidirectional current of one voltage to that of another voltage.

A second important object of the inven tion is to provide an improved apparatus of this character wherein regulation may be had of the voltage induced by the angular displacement of the second brushes.

WVith the above and other objects in view, as will be hereinafter apparent, the inven tion consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings and specifically claimed. 7

In the accompanying drawing like characters of reference indicate like parts in the several views, and

Figure 1 is a view disclosing the preferred rectangular form of element used in a transformer of this character.

Figs. 2 and 3 are diagrams showing one element and a complete assembly, the elements being shown circular the better to disclose the arrangement.

Each of the elements used in this transformer consists of a core forming a closed magnetic circuit consisting of halves A and B which are rectangular in form as shown in Fig. 1 and which may be termed annular. A cross bar or core G is employed which extends diametrically across the annulus and is in magnetic circuit therewith. On the halves of the annular portion are wound the primary windings D while secondary windings E are similarly wound on the cross bar, the primary windings being siX in number and the secondary being two in number.

In Fig. 3 three elements such as have just been described and, while in practice these elements will be of uniform size, and of the shape shown in Fig. 1, they are here shown as concentric, the better to disclose the arrangement. Also, for the sake of con venience, the elements are numbered respectively 1, 2 and 3 beginning with the inner element. By an inspection of this figure, it will be seen that each of the six primary windings D on 1 is connected in series to respective winding D on 2 and the latter is in turn connected to a respective winding 1) on 3. The windings D are thus arranged in six sets. At F are indicated the bars of a commutator and each set of windings D has one end connected to one bar and its other end connected to the next adjacent bar. In order to supply current to the commutator, contacts H are provided. At this time it will be noted that the sets of wind ings D and the commutator bars F are connected in series.

By reference to Fig. 3, it will be seen that the cross bars C of the several elements are displaced angularly 60 degrees and that each winding E on the cross bar of element 1 is connected in series to the windings E of elements 2 and 3, the windings E on the latter being also connected in series to the windings E on cross bar 1. Thus a closed series or ring is formed and between each succeeding two of the windings E is interposed a commutator bar G, these commutator bars being arranged when the machine is in operation, to successively engage contacts J so arranged that they may be shifted as indicated by the dotted line positions.

With this construction rotation of the several elements will cause successive engagement of the bars F with contacts or brushes H and if a direct current be supplied through these brushes successive current impulses will be sent through the windings D thus causing magnetic flux through the halves A and B and consequently through the cross bars C. Due to angular displacement of the cross bars and arrangement of windings, the direct current will cause induction of a secondary tri-phase current through a circuit connecting the contacts or brushes J and by moving these brushes to different positions the voltage across these brushes may be varied within given limits as desired, the position of maximum voltage being displaced 90 from the position of minimum voltage.

Having thus described the invention, what is claimed as new, is:

1. In a rotary transformer, the combination with a series of coaxial annular cores, forming a series of magnetic circuits and each having a cross bar in magnetic circuit therewith, said cross bars being angularly displaced with respect to one another, of windings on the annular cores connected in series from core to core, forming sets, series connections between sets, commutator bars connected with said series connections, brushes engaging the commutator bars and receiving direct current, windings on the cross bars to form secondaries, said windings being connected in series, commutator bars connected to the last series connections, and brushes contacting with the last mentioned commutator bars.

2. In a rotary transformer, the combination with a series of co-axial annular cores, forming a series of magnetic circuits and each having a cross bar in magnetic circuit therewith, said cross bars being angularly displaced with respect to one another, of windings on the annular cores connected in series from core to core, forming sets, series connections between sets, commutator bars connected with said series connections, brushes engaging the commutator bars and receiving direct current, windings on the cross bars to form secondaries, said windings being connected in series, commutator bars connected to the last series connections, and brushes contacting with the last mentioned commutator bars, said last brushes being shiftable to vary the voltage across said brushes.

In testimony whereof I affix my signature.

PARNELL RABBIDGE. 

